It's odd, and I haven't been able to reproduce it yet. In addition to Hanako's questions, what versions of Date Warp and Windows do you have? What color depth is your screen set to?

What exactly do you mean by fullscreened? Did it start running in fullscreen mode? Did you switch it into windowed mode before quitting?

Try going into your save directory (C:\Documents and Settings\(your username)\Application Data\RenPy\DateWarp\ or C:\Users\(your username)\AppData\Roaming\RenPy\DateWarp\) and renaming the file named 'persistent' and seeing if it will then start properly.

Looks like its been a while since the last post on this thread. Anyways, I recently bought Date Warp, and I got the same exact traceback.txt as Kirroha, except my game never once opened up or started. The demo worked fine on my system, but the full version doesn't.